The
new rules are a sharp change in policy for a state struggling to manage
one of the worst droughts in its history. They came after a winter in
which El Niño storms fell short of what meteorologists projected —
particularly in the southern part of the state — but still partly filled
parched reservoirs in Northern California and, more critically, partly
replenished the mountain snowpacks that provide water into the spring
and summer.

And Californians, responding to an executive order issued last April by Gov. Jerry Brown,
reduced their use of potable urban water by 24 percent compared with
2013 levels. Officials said they were hopeful that reduction would prove
permanent because of changes in water use such as replacing lawns with
drought-tolerant shrubs.

The rules, adopted by the State Water Resources Control Board,
are likely to mean a huge rollback — and in some places, an elimination
— of water reduction mandates that have forced people, businesses and
governments to curb watering of gardens and lawns, take shorter showers
and flush toilets less frequently.

State
officials said that the drought, already in its fifth year, was not
over and that Californians had to adapt to permanently more arid times
because of climate change.
Even as officials eased up on the regulations, the state made permanent
prohibitions against washing down sidewalks and driveways, using a hose
without a shut-off valve to wash cars and barring the use of water on
road medians.

“We
are still in a drought, but we are no longer in a
the-worst-snow-pack-in-500-years drought,” said Felicia Marcus, the head
of the state water board. “We had thought we are heading toward a
cliff. We were worried we were in our own Australian millennial drought. We wanted to make sure people didn’t keep pouring water on their lawns with wild abandon.”

Many
of the 411 water agencies across the state, even as they complied with
the mandatory cutback, had complained that the statewide requirement
failed to take into account water supply conditions, which vary widely
from region to region. And some, such as in Beverly Hills, with its
estates surrounded by sweeps of lawns and gardens, resisted at first,
but eventually complied.

Max
Gomberg, the climate and conservation manager for the board, said it
would review the order again in January and could return to mandatory
statewide reductions if communities revert to water-wasting habits or if
next year were dry again. Some meteorologists are predicting a weather
pattern next year known as La Niña, the opposite of an El Niño, meaning
that rainfall levels are significantly below normal.

“If
it’s looking like people have forgotten about the fact that there’s a
drought, and gone back to wholesale water wasting, we’ll take that into
consideration,” he said.

Tim
Quinn, the executive director of the Association of California Water
Agencies, applauded the rollback, saying statewide restrictions failed
to account for communities that had already taken steps to save water.

“This administration more than most listens, learns adjusts and improves,” he said.

“People will still continue a strong push for conservation,” he said. “It will be not quite as vociferous as it was.”

The
confidence on display was in many ways tentative, and raised the
prospect that officials could be sending mixed messages to a state that
had largely fallen in line after Mr. Brown, standing last year on a
barren field where snow was typically piled high, proclaimed the need
for the state to adapt to more arid times.

“We
saw some improvement,” said Michael Anderson, the state climatologist,
of the period from October to April when 90 percent of California’s
precipitation occurs. “But it was skewed north. There are definitely
some regions that will still have a tough time, because the rainfall
missed them.”

“The
snowpack is fading quickly,” Mr. Anderson said. “One of the challenges
has been the really warm temperatures. Our expectations are that those
will continue to become an increasing challenge in the decades ahead.”

Ms.
Marcus said that El Niño, while not saving the state, “gave us
something of a reprieve.” She said the board was correct in acting so
aggressively last year and that it could very well end up doing so
again.

“We
felt we really had to press the emergency brake in case we were going
to have a series of multiple dry years, “ she said.

“We’ve gotten a
great down payment on the future of dealing with climate change and
what’s coming at us.”"